Oil-still



W. M. DUNCAN.

OIL STILL.

APPLICATION FILED SEPT-10.1917.

1,342,941. Patented June 8, 1920.

2 SHEETS-SHEET I.

s Q I I i i I h s i 5% N m i N L Q i" :g I i I Q I I fZ'd7'ze5sx W. M. DUNCAN.

OIL STILL.

APPLICATION FILED SEPT- 10, 1911.

2 SHEETSSHEET 2.

WILLIAM M. DUNCAN, OF ALTON, ILLINOIS.

OIL-STILL.

Specification of Letters Patent.

Patented June 8, 1920..

Application filed September 10, 1917. Serial No. 190,553.

To all whom it may concern:

Be it known that I, l/VILLIAM M. DUN- HAN, a citizen of the United States, residing at vAlton, in the county of Madison and State of Illinois, have invented certain new and useful Improvements in Oil-Stills, of which the following is a specification.

The present invention has to do with certain improvements in oil stills and the like, but it willpresently appear that certain features of the invention are not limited to this particular class of service. They are, however, verywell adapted for this class of service, and I have, therefore, illustrated them in a particular application to this class of service and will describe such application, inasmuch as certain peculiar advanta es are derived therefrom.

n the treatment of oils by heating, as, for example, in cracking or distilling them in stills, very extensive use is made of the socalled bulk or still process. In practising this process, a considerable volume or quantity of the oil is placed in a tank or still, which is then heated at the desired temperature. During this process, more or less free carbon is liberated or pitch deposited, which carbon or pitch is deposited on the surface of the tank or still. This deposit rapidly thickens, so after a comparatively short time the interior of the tank or still is very thickly coated.

Now the carbon and pitch are very poor conductors of heat, so that a time is soon reached when it becomes very diflicult if not impossible to secure the desired temperature within the tank or still without the application of an excess temperature to the outside thereof. The heating is transmitted through the walls of the tank or still at such a slow rate that when the interior has become considerably caked it is not an uncommon thin for the sheet metal to become burned and thereby damaged and weakened. On account of the pressure existing within the tank, this burning and weakening often results in disastrous explosions with consequent loss of life and property.

I have discovered the fact that if the oil within the tank or still be kept in a fairly rapid circulation, it will be quite difficult if not impossible for any free carbon or pitch to deposit on the interior surface of the tank or still, so that the aforementioned serious objection to the tank or still process for the treatment; of the oil will be removed.

graduated for the I have furthermore discovered that this circulation of the oil may iently and effectively secured by pumping Oll around on the interior of the structure, withdrawing the oil from-the bottom port1on of the tank, and returning it to the upper portions of the tank, or vice versa. Such circulation may be convenientlyefi'ected, for example, by the use of a centrifugal pump located on the interior of the structure and operated by a suitable motor either inside or outside of the structure.

I have furthermore discovered the fact that if the oil is circulated at a point some distance above the upper surface of the oil within the tank or still, so that it is compelled to spray or discharge down onto the upper surface of the oil within the tank, the gases distilling off will be more readily and perfectly liberated because of the ensuing agitation to the material within the tank. Therefore, this additional benefit may be easily secured by so circulating the 011 as to return the same at a point somewhat above the surface of the body of the oil and in the form of a spray.

Other objects and uses of the invention Wlll appear from a detailed description of the same, which consists in the features of construction and combinations of parts hereinafter described and claimed.

Referring to the drawings Figure 1 shows a longitudinal vertical section through a tank or still, having applied thereto the features of the present inventlon.

2 shows a vertical cross section taken on line 2 2 of Fig. 1, looking in the direction of the arrows; and

' Fig. 3 shows a fra mentary lon itudinal section through one o the pipes an nozzles,-

showing how the size of the nozzle may be purpose to be presently explained. a

In the satisfactory application of the features of the invention which is illustrated in the drawings, there is provided a tank or still 4. Thesame may be of any suitable construction for this class of'work, and consequently I will not concern myself further with the detail of construction in this case. I will, however, explain that it may be provided with a dome or the like 5, through which the crude oil may be introduced from time to time, or which dome may be. used as a manhole to give ready acbe very convencess to the interior of the structure. The tank may also be provided with a gas outlet or discharge pipe (3, if desired. As a simple means of heating the tank, I have shown the gas pipe 7 having a series of burner openings 8, but it will be understood that the tank may be heated in any suitable manner, as by means of a furnace or the like. Therefore, I do not concern myself particularly with the method of heating the same.

In order to secure the aforementioned circulation of the oil, I have provided a pump or the like 9, which draws oil from one portion of the tank and returns it to another portion thereof. -In the particular construction illustrated, this is a centrifugal pump having a center inlet connection 10, and a peripheral discharge connection 11. The pump is shown as being mounted on the interior of the tank on the cross bar or beam 12. The shaft 1.3, which drives the impeller of the pump, extends up through a suitable stutling box 14 in the upper portion of the tank,'and is connected to a motor 15 by which it is driven. This motor may be'in the form of an electric motor supported on the cross beam 16, but it is evident that any suitable driving arrangement may be adopted. An intake pipe 1? extends throughout a suitable portion of the length of the lower portion of the interior of the. tank, and a discharge pipe 18 extends throughout a suitable portion of the length of the upper portion of the tank. 'lhe pipc 17 is connected to the intake connection 10, and the pipe 18 is connected to the discharge connection 11, of the pump. ()rdinarily the oil within the tank will stand substantially at the level shown by the line 13). Consequently, the oil discharged from the pipe 18 will be sprayed down onto the surface 15), which will keep the same in a constant state of agitation. Besides this, the oil so sprayed will be more perfectly vaporized and distilled by reason of the very act of spraying.

The intake pipe 17 is provided with a series of inlet nozzles 2H, and the discharge pipe 18 is provided with a series of discharge nozzles 21. These nozzles are all conveniently made in the form of nipples, facing downwardly and having bores communicating with the. interior of their respective pipes.

It is to be observed that on account of the fluid friction of the oil circulating within the pipes, there will be 'a natural tendency for the greatest amount of circulation to take place at a point closest to the pump, so that the circulation of the oil farthest removed from the pump will be more or less sluggish. In order to largely overcome this tendency and to equalize the circulation as much as possible throughout the entire length of the tank. any suitable expedient may be adopted, such as connecting the opposite ends of the pipes 17 and 18 to the respective connections of the pump. The

expedient illustrated in the drawing, howthe nipples are graduated from one end toward the other.

\Vhile I have herein shown and described only a single embodiment of the features of my invention, still it will be under tood that I do not limit myself in this embodiment, except as I may limit myself in the claims.

I claim:

1. In an oil still, the combination of a tank, an intake manifold on the interior of said tank and adjacent to the bottom thereof and having openings for the inlet of oil from various points adjacent to the bottom of the tank, a discharge manifold on the interior of the tank and adjacent to the top thereof and having openings for the discharge of oil at various points, said discharge manifold being above the normal level of the oil in the tank whereby the discharged oil is delivered onto the upper surface of the oil within the. tank, a centrifugal pump within the tank. and above the normal level of the oil. said pump having a vertical impeller shaft. connections from the intake and discharge manifolds to the pump, and a vertical driving shaft connec tion from the pump to a point above the tank, substantially as described.

2. In an oil still. the combination of a tank, an elongated intake manifold on the interior of the tank aml extending adjacent to the bottom thereof, and having a series of intake openings located adjacent to the bottom of the tank. a discharge manifold on the interior of the tank and having a series of discharge openings, said discharge manifold being located above the normal level of the oil in the tank, a centrifugal pump within the tank and located above the normal level of the oil, and having a vertical impeller shaft. and a vertical driving shaft extending up through the top of the tank, and direct connections from the intake and discharge manifolds to the pump located wholly within the tank. substantially as described.

WILLIAM M. DUNCAN. 

